///////////////////////////////////////////////////////////////////////////////////
/// OpenGL Mathematics (glm.g-truc.net)
///
/// Copyright (c) 2005 - 2015 G-Truc Creation (www.g-truc.net)
/// Permission is hereby granted, free of charge, to any person obtaining a copy
/// of this software and associated documentation files (the "Software"), to deal
/// in the Software without restriction, including without limitation the rights
/// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
/// copies of the Software, and to permit persons to whom the Software is
/// furnished to do so, subject to the following conditions:
/// 
/// The above copyright notice and this permission notice shall be included in
/// all copies or substantial portions of the Software.
/// 
/// Restrictions:
///		By making use of the Software for military purposes, you choose to make
///		a Bunny unhappy.
/// 
/// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
/// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
/// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
/// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
/// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
/// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
/// THE SOFTWARE.
///
/// @ref gtx_fast_square_root
/// @file glm/gtx/fast_square_root.inl
/// @date 2006-01-04 / 2011-06-07
/// @author Christophe Riccio
///////////////////////////////////////////////////////////////////////////////////////////////////

namespace glm {
    // fastSqrt
    template<typename genType>
    GLM_FUNC_QUALIFIER genType
    fastSqrt(genType
    x) {
    GLM_STATIC_ASSERT(std::numeric_limits<genType>::is_iec559,
    "'fastSqrt' only accept floating-point input");

    return genType(1) /
    fastInverseSqrt(x);
}

template<typename T, precision P, template<typename, precision> class vecType>
GLM_FUNC_QUALIFIER vecType<T, P>
fastSqrt(vecType<T, P>
const & x)
{
return
detail::functor1<T, T, P, vecType>::call(fastSqrt, x
);
}

// fastInversesqrt
template<typename genType>
GLM_FUNC_QUALIFIER genType
fastInverseSqrt(genType
x)
{
#		ifdef __CUDACC__ // Wordaround for a CUDA compiler bug up to CUDA6
tvec1<T, P> tmp(detail::compute_inversesqrt<tvec1, genType, lowp>::call(tvec1<genType, lowp>(x)));
return tmp.x;
#		else
return
detail::compute_inversesqrt<tvec1, genType, lowp>::call(tvec1<genType, lowp>(x)
).
x;
#		endif
}

template<typename T, precision P, template<typename, precision> class vecType>
GLM_FUNC_QUALIFIER vecType<T, P>
fastInverseSqrt(vecType<T, P>
const & x)
{
return
detail::compute_inversesqrt<vecType, T, P>::call(x);
}

// fastLength
template<typename genType>
GLM_FUNC_QUALIFIER genType
fastLength(genType
x)
{
GLM_STATIC_ASSERT(std::numeric_limits<genType>::is_iec559,
"'fastLength' only accept floating-point inputs");

return
abs(x);
}

template<typename T, precision P, template<typename, precision> class vecType>
GLM_FUNC_QUALIFIER T
fastLength(vecType<T, P>
const & x)
{
GLM_STATIC_ASSERT(std::numeric_limits<T>::is_iec559,
"'fastLength' only accept floating-point inputs");

return
fastSqrt(dot(x, x)
);
}

// fastDistance
template<typename genType>
GLM_FUNC_QUALIFIER genType
fastDistance(genType
x,
genType y
)
{
return
fastLength(y
- x);
}

template<typename T, precision P, template<typename, precision> class vecType>
GLM_FUNC_QUALIFIER T
fastDistance(vecType<T, P>
const & x,
vecType<T, P> const &y
)
{
return
fastLength(y
- x);
}

// fastNormalize
template<typename genType>
GLM_FUNC_QUALIFIER genType
fastNormalize(genType
x)
{
return x > genType(0) ? genType(1) : -genType(1);
}

template<typename T, precision P, template<typename, precision> class vecType>
GLM_FUNC_QUALIFIER vecType<T, P>
fastNormalize(vecType<T, P>
const & x)
{
return
x *fastInverseSqrt(dot(x, x));
}
}//namespace glm
